In the present day mass production of smaller and smaller printed circuit assemblies, there is a continued need for new and improved methods and apparatus for packaging electrical devices which can be readily machine inserted into or onto printed circuit boards or other circuit structures.
A number of diverse types of electrical devices have been packaged in small plastic housings with parallel electrical leads extending therefrom, and these packaged devices have been termed DIP's (Dual In-Line Packages). These DIP's are usually mass assembled by advancing a pair of lead frames or strips through one or more assembly stations whereat leads extending from the strips are bonded to passive or active electrical devices which may be housed in small dielectric plastic boxes.
One such assembly method is disclosed in copending application Ser. No. 974,152 filed Dec. 28, 1978, in the name of R. F. Kalina, wherein leads projecting from a spaced pair of carrier strips are heated and forced through opposed walls of a plastic box. Next, a rolled metallized film capacitor blank is moved within the box to deflect the leads against heat fusible end electrodes formed on the capacitor blank. Additional heat is applied to fuse the leads to the end electrodes whereafter the leads are severed from the carrier strips to provide discrete packaged capacitors which may be readily assembled to printed circuit boards.
Other examples of methods and apparatus for assembling dual in-line packages are illustrated in U.S. Pat. Nos. 4,003,125 and 4,012,835 both issued to C. W. Wallick, wherein small boxed circuit modules are terminated by advancing opposed blanks of lead frames of terminals toward and onto metallized pads formed along opposed outer sides of semi-conductor modules. The terminals are then soldered to the pads to interconnect the terminals with the circuit elements of the module. In general, dual in-line packages of this type are ultimately assembled with the leads extending through a circuit board so that the projecting portions of the leads may be wave soldered to circuit paths formed on the underside of the board.
Other electrical devices, such as coil bobbins, have been assembled with terminals by using the lead frame technique. U.S. Pat. No. 3,641,649 issued Feb. 15, 1972, to Busler et al. shows an assembly method wherein a continuous strip of groups of terminals interconnected by supporting sections is cyclically fed to advance each group of terminals into a flange of a coil bobbin, whereupon the terminals are bent and secured. Next, the supporting sections of the terminal strips are severed, leaving the terminals projecting from the bobbin flange.
In copending application Ser. No. 974,182, filed Dec. 28, 1978, in the names of W. J. Fanning and O. T. Masopust, Jr., there is disclosed a small metallized film capacitor which may be packaged in accordance with the present invention to provide a DIP type device that may be readily machine inserted in a printed circuit board or other circuit support.